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This issue of Knowlege-Based Systems brings together selected papers presented at the 4th annual Czechoslovak national conference 'Applications of Artificial Intelligence '89' (AI '89), which was held in Prague on 24-26 April 1989.

The conference was an important event, not just with regard to work on artificial intelligence in Czechoslovakia, but also from an international perspective. Of the 300 participants who took part in AI '89, 12 came from outside Czechoslovakia (from Hungary, the UK, the USA, the USSR and Vietnam). The Programme Committee selected 42 papers for presentation at the conference.

This issue does not aim to be comprehensive, but rather is intended to provide a snapshot of the professional atmosphere at the conference. Nine papers have been selected to represent different sections of the conference and different directions in AI research; three of these papers are by authors from outside Czechoslovakia.

Before discussing these selected papers in detail, it may be useful to consider briefly the history and current situation with regard to work on artificial intelligence in Czechoslovakia.

AI RESEARCH IN CZECHOSLOVAKIA Considerable research in the area of AI has been carried out in Czechoslovakia since the 1960s. Work carried out in the 1960s and 1970s on the Guha system for automatic hypothesis generation (developed by H~ijek, Havrfinek and others J) and research into adaptation, machine learning and pattern recognition led by Kotek 2 as well as the first text book by Havel 2° have had a considerable influence on later Czechoslovak AI research.

The Czechoslovak AI community is significant in size, being concentrated primarily in the major cities (Prague, Bratislava, Brno, Plzefi and Kogice), at nine universities and four institutes of the Czechoslovak Academy of Sciences (Mathematical Insitute, Prague; Institute of Information Theory and Automation, Prague; Institute of Technical Cybernetics, Bratislava and the Central Computational Centre, Prague). Splinters of the community are also to be found in different workplaces in industry and agriculture. Research carried out by members of the Czechoslovak AI community covers a wide spectrum of topics, but attention is focused primarily in the following areas.

Uncertainty processing in expert systems. Problems in this area are currently being studied by a group led by H~ijek at the Mathematical Institute. Hfijek developed the algebraic theory of uncertainty processing in rule-based expert systems 3, and together with Vald6s generalized this theory for the case of Dempster-Shafer's rules. The algebraic theory represents the extensional approach. On the other hand, a group led by Perez and Jirou~ek at the Institute of

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Information Theory and Automation prefers the intensional, 'purely probabilistic' approach to uncertainty processing 4.

Applications of expert systems. Several research groups have been engaged in projects devoted to the development of problem-oriented expert systems and expert system shells. A number of Czechoslovak diagnostic shells have appeared, notably:

• CODEX 5 developed by Popper and others (at the Research Institute of Medical Bionics, Bratislava),

• EQUANT 6 developed by H~ijek, H~ijkovfi, and Havr~inek (at the Czechoslovak Academy of Sciences),

• FEL-EXPERT 7 developed by Ma~ik and Zdr~ihal (at the Czech Technical University, Prague),

• SOLARIS 8 developed by Val~igek and Kokeg (at the Czech Technical University, Prague).

Considerable experience has been gathered by the practical applica- tions of these products in health-care, technical diagnosis, robotics and other areas. The incorporation of artificial intelligence into industrial practice has been made by the problem-oriented knowledge-based system TEPRO 9 for automated production plan- ning. This system has been developed at the Czech Technical University and is used by two major Czechoslovak companies (CKD and Tesla).

Knowledge acquisition. A statistical approach to the automated construction of the knowledge structure has been developed by Havr~nek at the Central Computational Centre. His recent work concerned the application of decomposable graph models for knowledge-representation purposes '°. On the other hand, the approach based on the automated decision-tree construction is preferred by Iv~inek and others 1' from the University of Economics, Prague, and by Zdnihal and others 12'~3 from the Czech Technical University, Prague. Kouba has experimented with a combination of both these approaches.

Speech recognition and understanding. Considerable effort has been devoted to the recognition of isolated spoken words at the Czech Technical University of Prague, the Technical University of Plzefi (by Psutka 14) and elsewhere. Work carried out by a group of mathematic- al linguistics (led by Sgall and Haji~ov~ ~5"16) at the Charles University of Prague, oriented towards speech understanding and machine translation, is well known throughout the world.

Programming in Prolog. Prolog is the most popular AI language in Czechoslovakia and several groups have used it to develop special-

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ized expert systems and other interesting AI pro~grams. Work by Jirk~ 17, ~t6p~nkov/t and ~t6pfmek 18 and Csonto ~ is particularly interesting in this respect.

In addition to the above major areas, research is also being carried out in Czechoslovakia into the problems of SIMD and MIMD hardware and software, computer vision and, particularly in the last two years, the problems of qualitative reasoning.

Despite being spread over different institutions, there is much cooperation within the Czechoslovak AI community. Regular semi- nars, workshops, conferences etc. are held to permit the presentation and discussion of results. Information is also exchanged at an international level.

DISCUSSION OF SELECTED PAPERS An overview of the probabilistic methods for uncertainty handling as well as a critical comparison is presented in the invited paper by Jirougek. Although the paper is written from a theoretical point of view, the practical aspects of implementations are taken into account.

The paper by Perez sharply criticizes the extensional interpretation of Dempster's combining rules usually used in MYCIN-like or PROSPECTOR-like expert systems.

The contribution by Vysok~ proposes a method of knowledge-base construction by exploration of the observational data in the case that only binary relations are considered. The 'classical' information theory is used to determine both the structure of the knowledge-base tree and the orientation of edges.

Kramosil considers the deductive power conserving transforma- tions of the Boolean-valued databases containing data and implica- tion rules.

The paper by Pospelov (from the USSR) has a deep philosophical background based on hermeneutics. It may invoke new ideas concerning knowledge representation and exploration in expert systems.

A method of nonmonotonic reasoning in Prolog is presented by Jirk~. The applicability and acceptability of this approach is widely discussed.

The contribution by Zejda and Lutcha describes a method of a model-based reasoning for fault diagnosis in a chemical plant. It is a work influenced by the causal modelling approach.

Finally, the two papers written by Laske and Brightman, respec- tively, (both from the USA) are outstanding notes on knowledge- based systems and creativity. They could be regarded as forming a section devoted to 'computer-aided creativity in the arts'.

Although the selected papers published in this issue can not provide a complete picture of the AI '89 conference, it is hoped that

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they will give a flavour of the event. In its entirety, the Czechoslovak AI national conference provides a wide platform for the exchange of new ideas on both a national and international level.

Vladimir Ma?ik Czech Technical University, Prague, Czechoslovakia

REFERENCES

1 H~ijek, P and Havr~inek, T Mechanizing hypothesis ¢brmation - mathematical foundations for a general theory Springer, Berlin-Heidelberg-New York (1978)

2 Kotek, Z et al Adaptive and learning systems SNTL, Prague, Czechoslovakia (198(]) - in Czech

3 H~ijek, P "Combining functions for certainty degrees in consulting systems' Int. J. Man-Machine Stud. Vol 22 (1985) pp 59-76

4 Perez, A and Jirou~ek, R "Constructing an intensional expert system (INES)" in Medical decision making: diagnostic strategies and expert systems North-Holland, The Netherlands (1985) pp 307-315

5 Popper, N and Gyarfli~, F 'CODEX---computer-based diagnostic expert system" in Plander, I (ed) A rtifieial intelligence and in]ormation-control systems of robots, North-Holland, The Netherlands (1984) pp 297-300

6 H~ijek, P, H~jkowi M, Havr~inek, T and Daniel, M "The expert system shell EQUANT-PC' Kybernetika Vo125 No l (1989) Supplement pp 4-9

7 Mai'ik, V and Zdr~ihal, Z 'The FEL-EXPERT and MIFELEX empty expert systems and their applications" in Working Paper WP-86-61 IIASA, Laxenburg, Austria (1986) pp 47-56

8 Koke~,, J and Vahi~k, M "Towards applications' in Mai'ik, V ~ed) Proc. AI '89 Conj,, Prague, Czechoslovakia (1989) pp 89-96

9 Kopeck#, P, Laiansk#, J, Ma/ik, V and Zdr~ihal, Z 'Knowledge-based system for computer-aided process planning' in Proc. Int. 1FA C Conf CSTD '85 Beijing, China (1985) pp 245-251

Ill Havr~nek, T 'On a general algorithm for model choice in multivariate analysis' Statistics Vol 19 (1988) pp 465-475

11 lv~inek, J and Stejskal, B "Application of the expert-ease system on observational dates and the comparison with the ESOD system" in Ma/'ik, V (edt Proc. AI '88 Conf. Prague. Czechoslovakia (1988) pp 125-132 - - in Czech

12 Zdr~ihal, Z ~Adquision dc conocimiento y aprendizaje inductivo' in Martin6z, A M, Morales, G and Zdr,'ihal, Z {eds) Primer curso internacional de sistemas expertos Cinvestav IPN, Mdxico (1987) pp 127-148

13 Mai'ik, V, Kouba, Z and Zdr~thal, Z 'Knowledge acquisition experiments under the FEL-EXPERT project' in: Plander, I (ed) Artificial intelligence and information-control systems of robots North Holland. The Netherlands (1987) pp 327-331

14 Psutka, J "Isolated word recognition' in Mai'ik, V (ed) Proc. AI '87 Con]~ Prague, Czechoslovakia (1987) pp 2 6 0 - 2 6 9 - in Czech

15 Haji~ov~i, E 'Focussing--a meeting point of linguistics and artificial intelligence' in Jorrand, P and Sgurev, V (eds) Artificial intelligence 11 - - methodology', systems, applications North Holland, The Netherlands (1987) pp 311-322

16 Sgall, P, Hajii~owi, E and Panevov~i, J The meaning of sentence in its semantic and pragmatic aspects Academia, Czechoslovakia and Reidel, The Netherlands (1986)

17 Jirkfi, P "FORBES - - an implementation of a frame-oriented rule-based expert system in Prolog environment" in MaHk, V (ed), Proc. AI '88 Conf. Prague, Czechoslovakia (1988) ~p 93-100

18 ~it~p~inkov~i, O and St6p~inek, P 'Transformations of logic programs' J. Logic Programming Vol 1 (1984) pp 305-318

19 Csont6, J, Mach, M and Viest, M "The implementation of an expert system in Prolog Environment' in Ma~'ik, V (ed) Proc. A1 '87 Conf. Prague, Czechoslovakia (1987) pp 132-137

20 Havel, I Robotics SNTL, Prague, Czechoslovakia (1980) - - in Czech

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